Pentek PD-1-20 Polypropylene Filter Cartridge, 20" x 2-1/2", 1 Microns Reduces sand, silt, scale, and rust particles in commercial drinking water and industrial fluid applications Nominal filtration rating of 1 micron Bonded polypropylene microfiber for resistance to chemicals and bacteria Initial pressure drop of less than 2 psi at a flow rate of 5 gpm Temperature range of 40 to 175 degrees F (4.4 to 79.4 degrees C)